Gap in the conditioned stimulus: Differential impacts on temporal expectancy in appetitive and aversive conditions in rats.

We analyzed, through a Pavlovian conditioning procedure in rats, the temporal pattern of behavior in appetitive and aversive conditions within subjects, and the difference in inferred temporal working memory functioning with the Gap paradigm. For both conditions, we paired a 60-s conditioned stimulus (CS: tone1 or tone2) with an unconditioned stimulus (US: shock or chocolate pellet) delivered 20s after CS onset. The analyses of mean response rate and individual-trial data were performed during Probe trials, consisting of CS alone, and trials in which gaps of different position or duration were inserted, to assess the effect of the temporal manipulation on behavior.

Neural encoding of time in the animal brain.

The processing of temporal intervals is essential to create causal maps and to predict future events so as to best adapt one's behavior. In this review, we explore the different brain activity patterns associated with processing durations and expressing temporally-adapted behavior in animals. We begin by describing succinctly some of the current models of the internal clock that can orient us in what to look for in brain activity.

Beyond Freezing: Temporal Expectancy of an Aversive Event Engages the Amygdalo-Prefronto-Dorsostriatal Network.

During Pavlovian aversive conditioning, a neutral conditioned stimulus (CS) becomes predictive of the time of arrival of an aversive unconditioned stimulus (US). Using a paradigm where animals had to discriminate between a CS+ (associated with a footshock) and a CS- (never associated with a footshock), we show that, early in training, dynamics of neuronal oscillations in an amygdalo-prefronto-striatal network are modified during the CS+ in a manner related to the CS-US time interval (30 or 10 s). This is the case despite a generalized high level of freezing to both CS+ and CS-.

Impaired cerebellar Purkinje cell potentiation generates unstable spatial map orientation and inaccurate navigation.

Cerebellar activity supported by PKC-dependent long-term depression in Purkinje cells (PCs) is involved in the stabilization of self-motion based hippocampal representation, but the existence of cerebellar processes underlying integration of allocentric cues remains unclear. Using mutant-mice lacking PP2B in PCs (L7-PP2B mice) we here assess the role of PP2B-dependent PC potentiation in hippocampal representation and spatial navigation. L7-PP2B mice display higher susceptibility to spatial map instability relative to the allocentric cue and impaired allocentric as well as self-motion goal-directed navigation.

Non-linear auto-regressive models for cross-frequency coupling in neural time series.

We address the issue of reliably detecting and quantifying cross-frequency coupling (CFC) in neural time series. Based on non-linear auto-regressive models, the proposed method provides a generative and parametric model of the time-varying spectral content of the signals. As this method models the entire spectrum simultaneously, it avoids the pitfalls related to incorrect filtering or the use of the Hilbert transform on wide-band signals.

Updating of aversive memories after temporal error detection is differentially modulated by mTOR across development.

The updating of a memory is triggered whenever it is reactivated and a mismatch from what is expected (i.e., prediction error) is detected, a process that can be unraveled through the memory's sensitivity to protein synthesis inhibitors (i.

Updating temporal expectancy of an aversive event engages striatal plasticity under amygdala control.

Pavlovian aversive conditioning requires learning of the association between a conditioned stimulus (CS) and an unconditioned, aversive stimulus (US) but also involves encoding the time interval between the two stimuli. The neurobiological bases of this time interval learning are unknown. Here, we show that in rats, the dorsal striatum and basal amygdala belong to a common functional network underlying temporal expectancy and learning of a CS-US interval.

Individual trial analysis evidences clock and non-clock based conditioned suppression behaviors in rats.

We analyzed the temporal pattern of conditioned suppression of lever-pressing for food in rats conditioned with tone-shock pairings using either a 10 or 15s conditioned stimulus (CS)-unconditioned stimulus (US) interval with a CS duration that was three times the CS-US interval. The analysis of average suppression and of individual trials was performed during Probe CS-alone trials and when a short gap was inserted during the CS. The pattern of suppression followed the classical temporal rules: (1) scalar property, (2) a shift in peak suppression due to a gap, compatible with a Stop rule, (3) a three-state pattern of lever-pressing in individual trials, with abrupt start and stop of suppression.

The amygdala: a potential player in timing CS-US intervals.

Pavlovian conditioning is the reference paradigm for the study of associative learning based on the programmed relation of two stimuli, the conditioned stimulus (CS) and the unconditioned stimulus (US). Some authors believe that learning the CS-US interval is a co-requisite of or a pre-requisite to learning the CS-US association. There is a substantial literature showing that the amygdala is a critical player in Pavlovian conditioning, with both aversive and appetitive USs.